Door lock



Oct. 26, 1937. R. s. HARTMAN DooR Loox Filed April s', 1954 2 Sheets-Sheet l vl M R 0 T T a Oct. 26, 1937. R. s. HARTMAN DOOR LOCK Filed April 9, 1934 ffv'rq, 7,

2 Sheets-Sheet 2 IIILII mm fw ma y. 5 m E WITNESS Patented Oct. 26, 1937 UNTED TA'iES assign DOOR LOCK Rush S. Hartman, Ewing Township,

Mercer 3 Claims.

The present invention relates to locks for use on doors of various classes such as those of trunks, cabinets, refrigerated compartments and doors of closed burden vehicles such as freight 5 cars, automobile vans, trucks, and the like, which require a strong and secure lock which will not open accidentally because of vibration or other causes.

On motor truck bodies my improved lock will hold a door tightly closed against vibration and by constantly retaining a pressure or pull on the door will automatically take up wear. It will also engage and draw the door up tightly when a twist or irregularity has occurred which would prevent an ordinary bolt from entering the keeper. It is also of especial value for use on refrigerated compartment doors Where a lock is desired which possesses the ability to draw the door to and maintain it in tightly closed position to prevent infiltration of heat and to retain a pressure even though wear or looseness has occurred, and where the ordinary type of lock is not effective thereafter.

Furthermore, in doors of this type rather heavy gaskets are generally employed which are usually so arranged that they must be tightly compressed in fully closing the door, and it is important that they be maintained in a compressed state by the lock to form a properly sealed closure. My improved lock is eminently suited for this purpose as it provides distinct mechanical advantages in the operation of finally seating and securely locking the door whereby such refrigerator door gaskets and the like are easily and quickly compressed between the door and its framie and thereafter maintained in compressed condition until released by unlocking the door.

A principal object of the present invention therefore is to provide an improved double action door lock comprising means operable to seat the door in the frame from a slightly ajar position and thereafter securely hold it seated and locked.

A further object of the invention is to provide a door lock having a movable latch member retractable within the connes of the door when the latter is opened but adapted for projection into a keeper in the door jamb when the door is being closed and then rotatable about a pivot 50 so as to engage the keeper and draw the door to fully closed position, and thereafter positively maintain it therein until it is desired to again unlock and open the door.

Other objects, purposes and advantages of the invention will hereinafter more fully appear or will be understood from the following description of certain embodiments thereof in which reference will be had to the accompanying drawings.

In said drawings: 5

Figs. 1 to 5 inclusive show one embodiment of the invention installed in a typical refrigerator truck door or the like, Figs. 1 to 3 being longitudinal sections through the door lock, its component parts and adjacent portions of the door '10 and door frame, showing the said parts in different positions assumed thereby at different periods in the operation of the lock.

More specifically, Fig. 1 shows the lock latch` member retracted into the door and the door 15 partially ajar;

Fig. 2, the latch member projected into the keeper with the door in substantially the same position as in Fig. 1, and

Fig. 3, thelatch member in engagement with 20 the keeper and the door fully seated in its frame and locked.

Fig. 4 is a staggered section on the line 4-4 in Fig. 3, line.3-3 in Fig. 4 indicating the plane of section in the preceding gures. 25

Fig. 5 is a fragmentary staggered section on the line 5--5 in Fig. 4.

Figs. 6 to 9 inclusive show another embodiment of my improved door lock but with the door and 30 frame omitted, Figs. 6, 7, 8 generally corresponding to Figs. 1-3 inclusive, and Fig. 9 being a rear elevation of the lock as shown in Fig. 7 with oertain parts broken away into section.

Figs. 10-13 show still another embodiment of 1 the invention, and respectively similarly generally correspond to Figs. 6-9 inclusive save that Fig. 13 shows the lock parts in` the position illustrated in Fig. 12.

Referring now more particularly to the drawings, the door D and frame F in Figs. 1-5 inclusive, form no part of the present invention and may be of any suitable type, those specifically illustrated being chosen for convenience in showing the manner of operation of this embodiment of the invention in association with a refrigerator truck door provided with a gasket G designed to be compressed against a substantially coextensive ledge L of the frame F when the door D is in locked position.

The lock itself, however, comprises a housing i, providing a substantially rectangular elongated chamber having flanges la at its side edges desirably spot-welded to a base plate 2, and substantially enclosing the principal Working parts, 255

screws 3, or other suitable means, being extended through the flanges and base plate to secure the lock to the door. -The lock is operated by a longitudinally slidable rod 4 actuated from any convenient means (not shown) such as a mechanical linkage or by direct connection to an operating handle, mechanical linkage being usually desirably employed when several locks are provided in one door to secure it to the frame at several points, since all the locks Amay thereby be simultaneously actuated from a Vsingle mechanism. The rod 4 extends into the housing I through a suitable aperture in one end thereof and is preferably surrounded by a coil spring 5 bearing against the interior of the housing ,at one end and against the head 6 of the rod at the other. This head 6 may be integral with or formed separately from and secured't'o the end of the rod 4 in any suitable manner, and provides a slot 1 for reception of a latch member actuating vpin-8, the ends of which pro-jects outwardly from the head 6 lthrough-the side plates of the latch member hereinafter more particularly described and into guide slots I in the side walls of the housing. As is clearly apparent from Fig. 1,

Athese slots extend substantially parallel `to the rod 4 through a portion Illa of their length and are of arcuate form through another portion IIJb .erably of hardened steel or other suitable wear resistant material, and comprises a body I2 having a toe I3 adapted for projection-into the keeper K in the door frame and a pair-of side plates I4, I5 vwhich lieinslidable engagement .with the respective side walls of the housing I when theV 4latch member is assembled therein, and are .pro-

vided with circular apertures for the reception of the pin 8. Adjacent the inner end of the toe I3, the latch member is also provided withintegral projecting bosses I6 which extend laterally outward in opposite directions through slots II in .the side walls of the .housing I and are Vslidable therein, these slots being parallel to the portions IUa of the slots Ill.

Theoperation of the lock just described may conveniently be explained by reference to Figs. 1-3 inclusive, assuming that the-` door initially is unlocked and slightly ajar, with the latch member retracted into the housingas shown in Fig. l. To lock .the door when it is thus nearly but Anot quite seated in its frame, the -rod 4 is moved longitudinallyas shownin Fig. 2, thereby correspondingly sliding the pin 8 forwardly in the slots I0 and projecting the latch member voutwardly from the door as thebosses I6 move forwardly through the slots I'I. When the bosses reach the outer ends of these slots -their further movement'is arrested-and they then form afulcrum or pivot about which the latch member swings upon further movement ofthe rcd, the pin 8 sliding laterally in the slot -`I of thehead 6 and the entire latch member rotating about the axis ofthe bosses I6 now at their outermost position in the slots I'I. The toe I3 ofthe latch member is thus brought into engagement with lthe bearing face 7c of the keeper K'and the door thereby forcibly drawn inwardly toward the however, the spring offers considerable resistance to the unlocking of the door although, of course, it will be understood that, if desired, any

.means other than the spring for retaining the latch'member in locked position may be employed or the spring may be positioned at any other convenient point suitable for producing the desired effect upon the lock mechanism.

As will be readily understood from the drawings, `when Ythe door is-to be unlocked prior to opening, the rod 4 is retracted, thereby rotating the latch member about its pivots I6 in a counterclockwise direction as viewed in Figs. 1-3 until restored to the position shown in Fig. 2, after which further retraction of the rod 4 draws the latch member into the housing and entirely releases the door. During the initial retraction or counter-clockwise movement of the latch member, the pin 8 travels along the curved surface IIlbl and the bosses I6 are thus held against the outer end of the slots I'I until the said movement is completed, this cooperation between pin 8 and surface IIJb` preventing `the possibility, which might otherwise be present, of the latch member moving bodily in a right line upon the initial retraction of the rod 4.

It may be noted at this point that the function of the slot I is to allow suflicient lateral movement of pin 8 to enable rod 4 to reciprocate in a right line which is usually desirable, but under certain conditions Where a slight angular movement of the rod is unobjectionable the connection between pin 8 and head or equivalent part 6 may be made directly and the slot omitted.

In the embodiment of the invention shown in Figs, 6-9 inclusive, substantially similar principles of operation are employed; no operating spring is indicated in these gures, however, since in this form of the invention it is usually more convenient to position the spring externally of the housing I' in case a spring is to be utilized at all. The housing is here provided with a depending flap Ib extending parallel to the base plate 2' and forming therewith bearing surfaces for the head 6 secured to the rod 4 whereby the head 6 is guided in its movement longitudinally of the housing. The head 6 preferably consists of a substantially rectangular bar having its for- Vward end tapered and provided with a T-slot 'I, the innersurfaces of which are rounded as clearly shown in Fig. '7.

The latch member I2 is provided with a rearwardly projecting web 28 having a transverse arcuate rib 2I extending laterally outward therefrom on either side of its rearmost edge and into the jaws of the T-slot 'I' in the head 6', while adjacent the inner end of the toe I3' is formed a semi-cylindrical groove 22 adapted to engage a pivot pin I6 xedly secured in the Walls of the housing I adjacent its outer end and bridging the chamber in the housing. The base plate 2 is apertured adjacent its outer end to provide a slot 23 for a purpose which will hereafter appear.

This embodiment of the invention is substan- JBO tiallyv similarI in operation to Ythat-.shown Tin Figs.

1 5, but' utilizes aV slightlywdifferent actionto effect therotation of the latch member about its pivot when the door is beingfinally seated. Thus, when the latch member I2'v is moved from the positionk shown in Fig. 6 to that shown in Fig. 7 by longitudinal movement of the headgthegroove 22A in the vlatchrnember is brought into engagement with the pivot pin I6' as the toe i3 of the latch member l2 is projected into the keeper K in the door frame. Further forward rightline movement of the latch member is now resisted by the pivot pin I8 and the latch member therefore rotates about the latter, the outer surfaces of the rib 2l sliding through the T-slot 1' in the head 6 and projecting the web 2li and rib 2l from the housing through the slot 23 provided for the purpose. During this rotation the toe i3 of the latch member engages the bearing face lc of the keeper K, drawing the door rmly into seated position and locking it therein. As shown in Figs. 6-8, the left hand portion of the rib 2l is outwardly curved at 24 to provide a stop adapted to engage the head 6' in the slot 'l' to prevent the latch member from being rotated too far if the door is open and thereby separating the latch member from connection with the head. By reverse movement of the head the door may be readily unlocked, the latch member initially rotating about its pivot I5 until restored to alignment with the housing, then moving longitudinally therein until the keeper is fully cleared and the latch member and associated parts are returned to the position shown in Fig. (i.

In the embodiment of the invention illustrated in Figs. -13 inclusive, a rack and pinion are utilized for actuating the latch member, and the head 6 is therefore preferably provided with a slot 3l) having teeth 3i forming a rack at its bottom, while the latch member i2" is provided with complementary teeth 32 of suitable width to enter the slot, a portion 32a of which are arranged on an arc described about the center of the semi-cylindrical pivot receiving groove 22', while another portion 32h is arranged substantially in a right line. As clearly apparent from Figs. 10-12 inclusive, projection of the head 6 downwardly in the housing i moves the latch member i2 outwardly therefrom until the groove 22' engages the pivot pin l secured to the housing whereupon the latch member is rotated about this pin through the action of the teeth 32a, the toe i3 thereby being brought into engagement with the bearing face k of the keeper K to fully seat the door, the teeth 32h being brought into mesh with the teeth 3i remote from the extremity of the head and further relative movement between the latch member and the head thereby prevented.

Retraction of the head through reverse movement of the rod t in releasing the lock rotates the latch member in the opposite direction about the pivot i6" until restored to the position shown in Fig. ll, and then retracts it into the housing to permit the door to be opened,

It will be apparent that my improved lock is adapted for use in many types of doors and other closures particularly where it is necessary or desirable that mechanical means be provided for fully seating the door in its frame, as in doors for refrigerator compartments or the like provided with resilient gaskets designed to be maintained under compression by the doors when closed. Thus, when the lock is employed in a door of such character, the action of the latch member in conjunction with they keeper first draws the door toward -theframe until fully seated therein, compressing `the gasket, and thereafter holds it firmly seated until released.

When a spring is used for effecting the-movement of the latch member, the actuating handle or other corresponding mechanism is generally provided with means for holding vthe, rod d, and hence the latch member, in retracted position against the pressure of the spring when the door is open, but such holding means are usually unnecessary when the spring is omitted and manually operated mechanisms solely utilized for positively moving the latch member.

Moreover, the several parts of my improved lock may readily be made by stamping, die casting, drop forging and like operations so that the amount of machine Work required is minimized, thus enabling the lock to be manufactured in commercial production relatively economically, while if the base plate be permanently secured to the housing by spot welding or otherwise at the factory after the parts are assembled, the lock then forms a unit which may be readily mounted in the door by the user.

While I have herein described certain embodiments of my invention with considerable particularity, it will be understood that I do not thereby desire or intend to limit or coniine myself in any way thereto as modications thereof will readily occur to those skilled in the art as well as changes in the form and arrangement of the several parts, and may be made if desired without departing from the spirit and scope of the invention as dened in the appended claims.

Having thus described my invention, I claim and desire to protect by Letters Patent of the United States:

l. A door lock of the character described comprising a housing, a latch member slidable therein having a portion adapted for projection therefrom, means operable to slide the latch member longitudinally of the housing comprising a rod having a slotted head and a pin loosely carried in said head, extending transversely through the latch member and having its ends respectively projecting into slots in the side walls of the housing, and a pair of bosses carried by the latch member and respectively projecting therefrom into other, substantially rectilinear, slots in said side walls, each of said first mentioned slots having a rectilinear edge and an arcuate edge adjacent thereto respectively adapted for cooperation with the pin to effect successive rectilinear and pivotal movements of the latch member relatively to the housing.

2. A door lock of the character described comprising a housing having opposed pairs of slots in its side walls, one pair of said slots extending longitudinally of the housing and the other pair having a portion similarly extending and another portion extending in a curve, a latch member slidable in the housing having a toe adapted for projection therefrom, bosses carried by the latch member respectively projecting into the first pair of slots, means for moving the latch member relatively to the housing comprising .a rod having a head provided with a slot, a pin extending through said slot and the latch member and having its ends projecting into the second mentioned'pair of slots whereby initial movement of the rod when the latch member is fully retracted in the housing is operative to slide the latch member longitudinally therein until the toe has passed out of the housing and said bosses engage the ends of the rst pair of slots, subsequent movement of the rod then serving to swing the latch vmember about said bosses as an axis to thereby bring the latch member to nal locking position.

3. A door lock of the character described comprising a. housing, a latch member slidable therein having a toe adapted for projection therefrom, means operable to slide the latch member longitudinally of the housing; means carriedby the housing forming a xed pivot for the-latch member, and-means cooperable withA said sliding means to effect pivotal movement of the' latch member about said pivot in the plane of its path of sliding movement after' said toe has been projected from the housing by such sliding movement.

RUSH S; HAR'I'MAN. 

